Inyentor



J 25, 1957 E. ERICKSON 2,797,252

IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINES Filed oct. 30, 19s;

uvmvrm ,Zdh ih [0273651020 IGNITION DEVICE FOR KNTERNAL COMBUSTION ENGINES Edwin L. Erickson, Aitkin, Minn, assignor of twenty-five percent to George H. Erickson, Aitkin,

Application October 30, 1353, Sierial No. 389,202 1 Claim. (Cl. 123-148) My invention relates generally to internal combustion engines and more particularly to improvements in ignition systems of internal combustion engines.

It is known to those skilled in the internal combustion engine art that, during general running conditions, the spark plugs of said engines are adjusted to provide a predetermined spark gap. In many instances, this gap is set between approximately .025 inch and .030 inch. In many instances, it has been found that, while a gap between these sizes is effective for more general running conditions, difficulty has arisen in providing sufficient voltage from the battery to create a spark of suflicient intensity between the spark plug electrodes to ignite the charge during starting of the engine inasmuch as the starting motor consumes a great deal of current during its operation. This is particularly true during cold weather when the stiffening of the lubricant in the engine sets up increased resistance of the parts thereof to movement by the starting motor, and when the lower temperature causes a decrease in the efficiency of the battery. In order that the battery may supply sufficient current to the starting motor to cause proper operation of the same, and also to cause creation of a spark of sufficient intensity to ignite the charge, it is desired that the resistance of the spark gap be lessened to a point where such a spark is possible. Thus, if the spark plugs are adjusted so that the gap between the electrodes thereof measured approximately .015 inch, a spark of sufficient intensity to ignite the charge could be created under quite severe conditions of battery inefiiciency.

However, it has been found that spark plugs adjusted to provide the minimum gap above noted tend to foul under normal running conditions for the reason that the resistance in the gap is relatively low and the spark created is of insufficient intensity to burn deposits which collect on the spark plug electrodes. The primary object of my invention is therefore the provision of a device by means of which spark plugs of an internal combustion engine may be operated under normal conditions with a minimum spark gap spacing suitable for producing a spark under adverse conditions. To this end I provide a high tension lead between the high voltage output of the ignition transformer and the ignition distributor, said lead comprising a pair of cooperating lead sections adjacent ends of which terminate in spaced electrodes which define a spark gap. I further provide an electromagnetically operated means for closing the spark gap in said lead during operation of the starting motor and for causing the gap to be opened when the starting motor is rendered inoperative upon starting of the internal combustion engine.

Other objects of my invention reside in the provision of a device for ignition systems as set forth which is relatively simple and inexpensive to manufacture, which is extremely easy to install in an ignition system, which is highly eflicient in operation, and which is rugged in construction and durable in use.

2,797,252 Patented June 25, 1957 ice The above and still further highly important objects and advantages of my invention will become apparent from the following detailed specification, appended claims and attached drawing.

The single view of the drawing is a diagram illustrating my invention and its application to the ignition system of an internal combustion engine.

Referring with greater detail to the drawing, an internal combustion engine is shown as comprising a battery 1, an ignition switch 2, an ignition transformer 3, an igniter 4, a distributor 5 and a plurality of spark plugs 6. The battery 1 has one of its terminals grounded to the engine or supporting frame therefor by a lead 7, and has its other terminal connected to the primary winding 8 by a lead 9 in which is interposed the ignition switch 2. The transformer 3 includes a secondary high voltage winding 10 which has one end connected to the opposite end of the low voltage primary winding 8 by a'lead 11.

The igniter 4 is of the type usually found in ignition systems for multiple cylinder internal combustion engines and comprises stationary and movable points 12 and 13 respectively the former of which is adjustably mounted in a bracket 14 that is anchored in the igniter casing 15, and the latter of which is secured to the outer end of an arm 16 that is pivotally connected to the casing as indicated at 17. The usual torsion spring 18 yieldingly biases the arm'16 in a direction of swinging movement toward'engagement of the contact 13 and 12. A motordriven cam 19 engages a finger 2ft onthe arm 16 and causes intermittent contact between the points 12 and 13. As shown, a lead 21 is connected at one end to the lead 11 and at its other end to the arm 16. The point 12 is grounded through a lead 22. A lead 23 grounds the arm 16 through the usual condenser 24.

The distributor 5 is of the type usually found in ignition systems of internal combustion engines and is connected to each of the spark plugs 6 by means of leads 25. Said spark plugs 6 are shown diagrammatically as comprising spaced electrodes 26 and 27 the former of which are connected to their respective leads 25 and the latter of which are grounded through the engine as indicated at 28. The distributor rotor which is operatively coupled to the cam 19 for common rotation therewith in the customary manner is shown by dotted lines and indicated at 29.

An electric starting motor M is shown as being connected to the battery 1 by means of a lead 30 and is controlled by suitable means such as a manually operated switch 31 and a solenoid operated starting switch 32. The starter switch 31 is interposed in a lead 33 which extends from the battery cable or lead 30 to a solenoid winding 34 which operates the switch 32 and which is grounded as indicated at 35. The circuit through the motor is completed through a grounded lead 36 in which is interposed the switch 32. Closing of the ignition switch 2 and the manually operated starting switch 31 causes energization of the transformer 3 and starting solenoid 34 respectively. When the solenoid Winding 34 is energized, the switch 32 is closed thereby causing energization of the starting motor M whereby to cause rotation of the crankshaft of the engine through the usual connections therebetween and the starting motor M. The engine is of the usual type and is indicated diagrammatically by dotted lines as at 37.

I provide a high tension lead 38 comprising a pair of cooperating lead sections 39 and 40 the former of which has one end connected to the high voltage output end 41 of the secondary winding 10 of the transformer 3, and the latter of which has one end connected to the input terminal 42 of the distributor 5. The other ends of the lead sections 39 and 40 terminate in electrodes 43 and 44 respectively that aremounted in a suitable casing 45 in predetermined spaced relationship toprovide aspark gap 46. A bridge connector- 47 of suitable electrical conducting material is supported from the outer end of an arm 48- by means of an'insulator -49 and-is adapted to be moved into and'out of bridging-engagement or: contact with the electrodes-43:and-44'to close'and open-the gap 46 therebetween. The arm 48 is pivota-llymountedin' the-casing 45 as indicated at '50'=and is-adapted to-be moved by an actuatorin the-nature o'f anelectroma-gnet 51 mounted in the casing-45. 'The electromagnet51 is interposed in a circuit comprising alead 52 which is connected to'the grounded side of the starter switch 31 and which -at its other end is grounded as'indicated at 53.

With .this arrangement, .energization' of the electromagnet 51 oocurs-onlywhenthe starter-switch 31"is closed to cause bridging of the gap 46by the connector 47. Deenergization of the electromagnet 51 will permit the arm 48 and connector 47-thereon to drop by gravityaway from bridging contact with the electrodes-43 and 44. If desired, any suitablemeanssuch as a spring, not shown, may be used to move the arm 48 away from such engagement of the bridge connector 47 with the electrodes 43 and 44 when the electromagnet 51 is dc-energized.

Theme of the high tension lead sections 39- and 40, the gap-forming electrodes 43 and 44, the bridge ,connector 47 and actuator 51 therefore as above described makes possible the setting of the electrodes 26 and 27 of the several spark plugs 6 in a manner to provide a gap therebetween over which a spark of suitable intensity will jump under extremely adverse starting conditions. When the starter switch 31 is closed, the motor M is energized to rotatethe crankshaft of the engine 37. Meanwhile the electromagnet 51 is energized to cause bridging of the spark gap 46 permitting unimpeded flow of current from the winding 10 to the distributor 5. The voltage to the spark plug 6 during the starting is, under adverse starting conditions, relatively low, the greater part of the current from the battery being consumed in operating of the starting motor M. When the engine 37 starts to operate, the starter switch 31 is released thereby causing de-energization of the starting motor M in the usual manner and simultaneous de-energization'of the electromagnet 51, resulting in breaking the bridging contact between the connector 47 and the electrodes 43 and. The battery 1 being relieved of the load imposed thereon by the starting motor M provides a greater voltage output to the secondary lead38. As the current'must'pass the air gap 46 between the electrodes 43 and 44, the

characteristics of the spark between the spark plug electrodes 26 and 27 remain substantially the same as formerly and the spark plugs 6 operate in a normal fashion. With the above arrangement fouling of the spark plugs is obviated and a long life of the spark plug electrodes 26 and 27 is assured.

My invention has been thoroughly tested and found to be completely satisfactory for the accomplishment of the objectives set forth; and while I have shown and described a preferred embodiment of my novel device, it will be understood that the same is capable of modification without departing from the spirit and scope of the invention as defined in the claim.

What I claim is:

In a multiple cylinder internal combustion engine, having an ignition circuit comprising, a spark plug for each cylinder, a battery, an ignition transformer having a low voltage input and a high voltage output, and a distributor having a common lead to the high voltage output of theigniti'on transformer and a lead to each of the spark plugs, said engine further having a starting system comprising a'starting motor and anormally open circuit :for said motor comprising said battery and a normally open manually operable starter switch; the improvement comprising in combination with the ignition circuit of a pair of spaced electrodes interposed in the common high'voltage lead and defining a spark gap in said common high voltage lead, a bridge connector for said electrodes, means including an insulator element mounting said bridge connector for movements between a normally inoperative position spaced from said electrodes and an operative position in bridging contact with said electrodes, an electromagnetic actuator operative to impart movement to said bridge connector toward bridging engagement with said electrodes, and circuit means for connecting said actuator to the battery, said circuit means being under control of the starter switch to be energized by the battery coincidentally with closing of the starting motor circuit and to be deenergized coincidentally with opening of said circuit, whereby to cause closing of said spark gap by said bridge connector only during the period of energization of said starting motor.

References Cited in the file of this patent UNITED STATES PATENTS 

